计算机科学与技术系

Department of Computer Science and Technology

Education background

Bachelor of Computer Science & Technology, Tsinghua University, Beijing, China, 1996;

Master of Computer Architecture, Tsinghua University, Beijing, China, 1998;

Ph.D. in Computer Architecture, Tsinghua University, Beijing, China, 2001.

Social service

Professor and Ph.D. candidate supervisor at Department of Computer Science & Technology, Tsinghua University

Part-time graduate student supervisor at School of Software and Microelectronics, Peking University

Joint Ph.D. candidate supervisor at Shandong University

Editorial member of Computer Applications and Software(in Chinese), China Science Paper(in Chinese) and Networking Science by Springer

Guest editor of the Special Issue on Network Virtualization of IEEE Network

Senior member of IEEE

TPC member of IEEE GLOBECOM, IEEE ICCCN, IEEE ISCC, etc.

Senior member of China Computer Federation and member of its Academic Work Committee, Internet Special Committee and Services Computing Special Committee

Areas of Research Interests/ Research Projects

New Generation Network Architecture

Network Routing, High Performance Routers

P2P and Overlay Network

Internet of Things(IoT)

Network virtualization and optimization

National Natural Science Foundation of China: Research on Internet Resource Management and Optimization Methods towards Both Fairness and Efficiency (2010-2012);

National 863 High-Tech Program: Development Environment of Reconfigurable Routing Switching (2008-2010);

CNGI Project by National Development and Reform Commission: Standardization System for Real IPv6 Source Address Validation (2008-2010).

Research Status

In recent years, I have mainly engaged in the research and teaching of computer network architecture and new generation network. My main research achievements are as follows:

1. Research on the Scalable and Reconfigurable High-performance Routing and Switching Technology.

This research presents a BGP implementing model based on the scalable routing and switching System, which has a higher speedup ratio compared with that of the previous proposals.

It proposes the function module division and system development method at three levels – sub-component, component and macro-component – based on the characteristic of routing and switching software. Compared with other methods, this one raises the code reuse proportion and efficiently reduces the routing system development cost. From this research, six patents of invention have been granted.

The scalable and reconfigurable high-performance router software platform has better compatibility, and provides developing and testing tools with higher performance efficiency compared with Cisco IOS system and MIT Click platform, respectively. The result helped win the Science and Technology of Electronic Information Award by the Chinese Institute of Electronics (first class) in 2012.

This software platform has been applied to routers of Bitway Networking Technology Co., Ltd., and adopted by network operators, such as CERNET2, China Telecom, and China Mobile, realizing desirable economic and social achievements. Many communication companies have also adopted this software when developing products or testing performance, including H3C, Ruijie Networks and Maipu Communication Technology Practical application by these companies shows “the application of this platform greatly improves development efficiency and accelerates research progress.”

2. Research on P2P Network Traffic Classification & Management and Live Streaming Technology.

This research proposes a new P2P network traffic estimation model, which possesses higher estimation accuracy than the recently proposed gravity and independent connection model. A P2P network traffic classification method is proposed based on P2P networks’ transmission behavior. This method has a simpler approach to classification with a higher success rate than the best result of previous classification methods proposed based on the Bayes’ Theorem. The paper has been cited for ten times since it was published in Computer Communications. A cache replacement algorithm based on P2P network live streaming media is proposed; it has higher cache efficiency than the previous representative cache method based on segments.

A node selection and a transmission scheduling method based on P2P network live streaming media are proposed, solving the problem that the traditional random selection method can hardly guarantee the transmission quality of streaming media and being granted two patents of invention. Based on this achievement, Prof. Xu’s group and PPLive cooperated to develop and implement the cross-platform P2P video accelerator, PPVA. According to the measurement and statistics of the PPVA website, there have been 280 million times of downloading this software, which supports thousands of video web sites invisibly with more than 10 million on-line users downloading videos every day, effectively saving the network broad-band of video web sites and network operators.

3. Research on Internet Traffic Management.

Network multipath traffic management and optimal traffic engineering are studied based on Network Utility Maximization (NUM) theory, which leads to the multipath traffic management method based on the logarithmic barrier method. The multipath traffic management method can realize theory optimization and convergence assurance simultaneously that the previous representatives, including TRUMP, can’t achieve.

A new load balancing in proportion method based on traffic engineering is proposed, getting a new conclusion that the optimal routing in load balancing in proportion is the routing with the shortest M/M/1 queuing delay. Based on this conclusion, the optimal traffic engineering can be realized through routing protocols designed to find the shortest path, such as OSPF, in network engineering.

Honors And Awards

The Talent Award by China Venture Investment Corporation Software Engineering (2012)

The Young Scientist Award by China Computer Federation(2011)

Nova Program of Science and Technology by City of Beijing (2007);

Ministry of Education: New-Century Talents Award (2008);

Science and Technology Progress Award by China Institute of Communications, First Class-IPv6 Core Router (2004);

National Science and Technology Progress Award, Second Class-IPv6 Core Router (2005);

China Computer Federation: Wang Xuan Award, First Class-IPv6 Core Router (2006);

Annual China University-Wide Top-Ten Science and Technology Achievement Award-RFC 5210, International Standard of Key Technologies in Next-Generation Internet (2008).

Academic Achievement

1. Journal and Magazine Publications

[1] Xu Ke, Zhu Min, Hu GuangWu, Zhu liang, Zhong YiFeng, Liu Ying, Wu JianPing, Wang Ning, Towards Evolvable Internet Architecture-Design Constraints and Models Analysis (accepted), Science China, 2014.

[2] K Xu, W Chen, C Lin, M Xu, D Ma, Y Qu. Towards Practical Reconfigurable Router- A Software Component Development Approach (accepted)[J]. Network, IEEE, 2014.

[3] Xu K, Shen M, Cui Y, et al. A Model Approach to the Estimation of Peer-to-Peer Traffic Matrices[J]. Parallel and Distributed Systems, IEEE Transactions on, 2013.

[4] Xu, K.; Zhong, Y.; He, H., "Can P2P Technology Benefit Eyeball ISPs? A Cooperative Profit Distribution Answer[J]," Parallel and Distributed Systems, IEEE Transactions on, 2013.

[5] Hu G, Xu K, Wu J, et al. A general framework of source address validation and traceback for IPv4/IPv6 transition scenarios[J]. Network, IEEE, 2013, 27(6): 66-73.

[6] Wang H, Wang F, Liu J, et al. Accelerating Peer-to-Peer File Sharing with Social Relations[J]. Selected Areas in Communications, IEEE Journal on, 2013, 31(9): 66-74.

[7] XU Ke, Hongying Liu, Jiangchuan Liu, Jixiu Zhang, “LBMP: A Logarithm-Barrier-based Multipath Protocol for Internet Traffic Management,” IEEE Transactions on Parallel and Distributed Systems 22(3):476-488 2011.

[8] LI Dan, WU Jianping, LIU Jiangchuan, CUI Yong, XU Ke, “Defending Against Distance Cheating in Link-Weighted Application-Layer Multicast,” IEEE/ACM Transactions on Networking 19(5):1448-1457, 2011.

[9] XU Ke, Ming Zhang, Jiangchuan Liu, Zhijing Qin, Mingjiang Ye, “Proxy Caching for Peer-to-Peer Live Streaming,” Computer Networks 54(7):1229-1241 2010.

[10] LIU Jiangchuan, WANG Haiyang, XU Ke, “Understanding Peer Distribution in the Global Internet,” IEEE Network July/August 2010.

[11] XU Ke, Ming Zhang, Mingjiang Ye, Dah Ming Chiu, Jianping Wu, “Identify P2P Traffic by Inspecting Data Transfer Behavior,” Computer Communications 33(10):1141-1150 2010.

[12] XU Ke, Mingwei Xu, Qi Li, Song Lin, “Analysis and Case Study on Multi-dimensional Scalability of the Internet Architecture,” Science in China Series F: Information Sciences 51(11):1661-1680 2008.

[13] XU Ke, Huan He, “BGP parallel computing model based on the iteration tree,” The Journal of China, Universities of Posts and Telecommunications 15(Suppl.): 1–8 2008.

[14] MA Zhen, Ke Xu, Jiangchuan Liu, Haiyang Wang, “Measurement, modeling and enhancement of BitTorrent-based VoD system,” Computer Networks 56:1103–1117 2012.

[15] HE Huan, Ke Xu, Ying Liu, “Internet resource pricing models, mechanisms, and methods,” Networking Science 1(1-4):48-66 2012.

[16] HUANG Yan, Ke Xu, Haitao Li, Yang Cao, Xin Yao, “Large-scale P2PVOD system: Focusing on clients,” SCIENCE CHINA-INFORMATION SCIENCES 54(8):1677-1690 2011.

[17] LI Suogang, Ke Xu, Ying Liu, Jianping Wu, “Edge Overlay Multicast to Support Comparable Multi-class Services,” Journal of High Speed Networks 17(1):13-36 2008.

[18] LIU Chunyu, Ke Xu, “Framework for End-to-End Optimal Traffic Control Law Based on Overlay Mesh,” Journal of Communications and Networks 9(4): 428-437 2007.

[19] CUI Yong, Ke Xu, Jianping Wu, Linjian Song, “CBroadcast: an Application Layer Multicast Mechanism based on Combination of Central Control and Self-organization,” International Journal of Ad Hoc and Ubiquitous Computing 2(4):232-238 2007.

[20] WU Jianping, Ke Xu, “Next-generation Internet Architecture,” Journal of Computer Science and Technology 21 (5): 723-731 2006

2. Conference Publications

[1] Guangwu Hu, Ke Xu, Jianping Wu, A Controllable, Manageable and Scalable Architecture for Large-scale Enterprise Networks.IEEE HPCC,2013.

[2] Ke Xu, Min Zhu, Ning Wang, Song Lin, Haiyang Wang, Tong Li, The 2ACT Model-based Evaluation for In-network Caching Mechanism. The IEEE symposium on Computers and Communications (ISCC), 2013.

[3] MA Zhen, Ke Xu, Yifeng Zhong, “Exploring the Policy Selection of P2P VoD System-A Simulation based Research,” IEEE/ACM IWQoS 2012.

[4] XU Ke, Hongying Liu, Jiangchuan Liu, Meng Shen, “One More Weight is Enough: Toward the Optimal Traffic Engineering with OSPF,” IEEE ICDCS 2011.

[5] XU Ke, Meng Shen, Mingjiang Ye, “A Model Approach to Estimate Peer-to-Peer Traffic Matrices,” IEEE INFOCOM 2011.

[6] XU Ke, Haitao Li, Jiangchuan Liu, Wei Zhu, Wenyu Wang, “PPVA: A Universal and Transparent Peer-to-Peer Accelerator for Interactive Online Video Sharing,” IEEE IWQoS 2010.

[7] Haiyang Wang, Jiangchuan Liu, Bo Chen, Ke Xu, Zhen Ma, “On Tracker Selection for Peer-to-Peer Traffic Locality,” IEEE P2P 2010.

[8] LI Haitao, Ke Xu, James Seng, Po Hu, “Towards health of replication in large-scale P2P-VoD systems,” IEEE IPCCC 2009.

[9] XU Ke, Xiaowei Ma Chunyu Liu, “A Hash Tree Based Authentication Scheme in SIP Applications,” IEEE ICC 2008.

[10] XU Ke, Minpeng Qi, Haitao Li, Peng Yang, Hui Deng, “A Novel Interfacing Solution to Make IKEv2 Work in MIPv6 Environment,” IEEE ICC 2008.

[11] XU Ke, Yahui Yang, Tao Chen, “Improving BitTorrent Network's Performance via Deploying Helpers,” IEEE/IFIP International Conference on Embedded and Ubiquitous Computing 2008.

[12] XU Ke, Jiangchuang Liu, Lizheng Fu, Chunyu Liu, “On the Stability of Application-layer Multicast Tree,” ISCIS 2006, LNCS4263 2006.

3. Books

[1] XU Ke, Yifeng Zhong, Huan He, Internet Resource Pricing Models. Springer, 2013.